Macroheterocycles. Part 42. A facile synthesis of dihydroxy cryptands and their dehydroxylation

Abstract

A facile synthesis of hydroxy cryptands by the reaction of diglycidyl ethers with a diazacrown ether is reported. The reaction results in a mixture of bi- and tri-cyclic cryptands which can be separated by chromatography. The yield of bicyclic cryptands is lowered with a decrease in the diazacrown ether cycle size and an increase in the number of oxyethylene moieties between the epoxy groups in the diglycidyl ether. The results are interpreted in terms of the intramolecular hydrogen bonding of epoxy groups promoting the steric fixation of the reaction centres. Dehydroxylation of the bicyclic dihydroxy cryptands has been performed by means of chlorination followed by reduction.